The Grenada gazette. (Grenada, Miss.) 1885-18??, 1887-07-30
CABLE RAILWAYS,
The C~Ontrivances That Go to the Equip
ment of City Cable Roads.

The ContrIvances Tina Go to the Equip
ment Of CITY Cable Roads.
In order to start with a clear under.
standing Of the situation, take two
empty spools and stand them on end
a few inches apart upon a board.
Through the hole in the middle of
each drive a stout pin or a wire nail
into the board. Pass a thread around
the spools. and tie its ends together so
thatit will be moderately tight around
them. Now if spool number one is
made to revolve, the thread will move
and spool number two will revolve
with it. Here you have a moving ca
BILE in miniature. If a line of rails
were laid under each thread the model
would be still nearer reality. But this
is the very simplest situation possible:
the line is straight and level from end
to end, and the cable is above ground
which would not do at all where or
binary street traffic would be inter-
fered with. Moreover we can not gen.
orally have u engine house spool
number one, for instance) in the mid
die of the street.
Let us in the first place. get the en-.
CINE house out of the way, or in other
words, make the cable turn a corner.
All that is needed is to lead each cable
around a spool set at the desired cor-
ner. The spool number M (the en-.
gine house, is set wherever v
lent, and when it is made to revolve,
all the other spools revolve with it
and with the cable.
But cable and spools are still above
ground, so when we are using a real
street we dig a long trench and lay an
iron pipe or tunnel therein. On the
floor Of this tunnel we set grooved car-
rying wheels for the cable to rest upon,
and in the top of it we leave a narrow
slit open, through which we can reach
down with a pair of tongs, as it were,
attached to the car, and grip the NOV.
ing cable. OF course pits are digged
for the spools, or rather for the large
grooved wheels that take their place
in actual construction. We have
now provided for a straight and level
main line, but if the street
is crooked, or II there are any changes
of level the cable will rub against the
sides or top of the tunnel where the
bend occurs, and will Don wear out
itself and the tunnel, too. This diff
ficulty is overcome by setting wheels
like the carrying pulleys at the sides OF
the tunnel or in its roof wherever the
change of direction would naturally
cause the cable to touch.
Nothing now remains but to start
the engine, grip the moving cable with
your tongs, and away you 60! So
thought one Of the early inventors
who contrived q tunnel and carrying
pulleys. and the rest about MS they are
used to-day. but who remarked in his
claim, 'the method Of attachment is
immaterial." In point Of fact. it is
excessively material. The gripper must
be immensely strong. and its
grip must be vise-like; yet it
must not tighten all at once
or the car will start with such q jerk
that all the passengers will be piled at
the rear end. The gradual tightening
can be effected with solid jaws, but
they wear ont costly cable SO rapidly
that in some instances cables have be-
come useless in less than three months.
Endless experiments have been
made, and the best results have been
attained on the bridge between New
York and Brooklyn where the traffic is
continuous day and night, with heavy
trains at intervals, during the busy
hours, of ono minute and a half. The
first cable that was set in motion over
the bridge lasted three years, and even
then showed few external signs Of
wear. The inside strands had. however.
been crushed by pressure and the cable
had stretched beyond the limit Of
safety.-C L. Norton. in Nautauquan
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